The development and application of software radio are described in this paper. In order to satisfy the numeralization need of communication intermediate frequency receiver, the design scheme of 560MHz IF digital receiver in S-band communication system which designed by the software radio idea is introduced, the basic principles and key techniques are analyzed, the functional block diagram and the specific implementation method of the communication are put forward. The whole system which is already applied in a S-band communication system is highly integrated, reliable and flexible.